Field of the Invention
The present invention relates to an image forming device and a program.
Description of the Related Art
In an electrophotographic image forming system, when the toner in the developing device is deteriorated, a problem such as degradation of image quality or toner spilling is caused. As such, the toner in the developing device is replaced in a certain amount or more when a certain period of time passes (which is called toner refreshing).
For example, a technology has been proposed in which when image formation of low coverage images is continued with use of cut sheets of paper, an image pattern named refresh band is created between sheets to forcibly consume toner to thereby replace the toner in the developing device (for example, see JP 2014-149487 A).
However, when attempting to apply the aforementioned technology to continuous paper, as a refresh band is created at an unexpected portion between images on the sheets, it is not preferable. Furthermore, in a configuration having a separation mechanism for separating continuous paper from a transfer unit, it is possible to create a refresh band in a state where the transfer unit is separated from the continuous paper. However, an interruption process or the like is involved, whereby blank portions (gaps between images) are generated at a plurality of locations on the continuous paper, which lowers the productivity.
As such, a fixed upper limit value (e.g., 300 m) of a paper passing distance of continuous paper may be set, and when the upper limit value is reached, refresh bands may be created collectively on the continuous paper.
As a result, it is expected to prevent blank portions from being generated at a plurality of locations and to suppress lowering of the productivity. Moreover, in the case where a job has a length exceeding the fixed upper limit value, it is possible to present, to the user, a fact that blank portions will be generated due to interruption during a job, and an option of cancelling the job.
However, even when an upper limit value is reached, there is a case where a job can be completed without need of creating a refresh band and without any blank portions, depending on the coverages of the images constituting a job. Even in such a situation, with a configuration in which a refresh band is created whenever the upper limit value is reached, a user may cancel the job uselessly, which leads to lowering of the productivity.